Cold temperatures don't mean all lake ice is safe

OTSEGO COUNTY - "We've had a cold snap lately," said Otsego County Sheriff Jim McBride, "but don't let that deceive you. It still takes a while for the ice to freeze to a point where it's safe."

When temperatures do get cold enough for the water to freeze, winter sports enthusiasts should always check before venturing out onto ice. Ice can form in several different conditions, and some are more perilous than others. Clear ice is the strongest, formed by a long, hard freeze, and can vary in color from green, blue and black, depending on the water color beneath the ice.

Frazil ice is usually the first type to form when temperatures drop, and is made up of disk-shaped crystals which form a thin film, eventually forming a solid sheet of ice.

Snow ice is low in density and porous and is very weak. Layered ice is just that, many layers of frozen and refrozen snow - with a striped appearance.

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McBride offered these tips to ice fishermen, snowmobilers, ice skaters, or anyone who goes out on the ice:

€ Never go out alone.

€ Test the ice with a spud every few feet - thickness can change in that short of a distance.

€ Wear a life preserver or a float-coat.

€ Attach a 20- to 25-foot-long rope to your waist and let it drag behind you - it won't interfere and it's something that someone can grab should you fall through.

The notion that ice thickness is the only factor determining ice strength should be discarded once and for all, according to McBride. "Thick ice does not necessarily mean safe ice," said Sheriff McBride.

Because ice seldom freezes at the same rate in the same body of water, it is not uniformly thick from one location to another. Ice can be one foot thick in one location, and only one inch thick just 10 feet away. According to experts, new ice is usually stronger than old ice, and grows thicker and stronger during formation. As ice decays, it becomes unsafe even though it may appear thick.

€ Underground springs - Many Michigan lakes are spring-fed, and the warmer temperatures of the spring water can cause the ice to weaken from underneath. Entrances of streams and dams can also cause the ice to be unstable in those locations.

€ A thick blanket of snow can actually insulate the surface against freezing, causing the ice to form more slowly or even deteriorate.